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1.
J Int Soc Sports Nutr ; 21(1): 2296888, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38131124

RESUMO

OBJECTIVE: The purpose of this study was to examine the acute effects of a multi-ingredient, low calorie dietary supplement (MIDS, XTEND® Healthy Hydration) on 5-kilometer (5-km) time trial performance and blood electrolyte concentrations compared to a carbohydrate-electrolyte beverage (CE, GATORADE® Thirst Quencher) and distilled water (W). METHODS: During visit 1 (V1), participants (10 men and 10 women, 20-35 years old, BMI ≤ 29 kg/m2, recreationally active) reported to the laboratory whereby the following tests were performed: i) height and weight measurements, ii) body composition analysis, iii) treadmill testing to measure maximal aerobic capacity, and iv) 5-km time trial familiarization. The second visit (V2) was one week after V1 in the morning (0600 - 0900) and participants arrived 12-14 h fasted (no food or drink). The first battery of assessments (V2-T1) included nude body mass, urine specific gravity (USG), a profile of mood states (POMS) questionnaire, and the completion of a visual analogue scale (VAS) questionnaire to quantify cramping. Then heart rate (HR), blood pressure (BP), total body hydration (via bioelectrical impedance spectroscopy [BIS]) were examined. Finally, a measurement of blood markers via finger stick was performed. Participants consumed a randomized beverage (16 fl. oz. of MIDS, 16 fl. oz. of W, or 16 fl. oz. of CE) within 3 min followed by a 45-min rest. Following the rest period, a second battery (V2-T2) was performed whereby participants' USG was assessed and they completed the POMS and VAS questionnaires, and HR, BP, and blood markers were measured. The participants then performed a 5-km treadmill time trial. Immediately following the 5-km time trial, participants completed a third testing battery (V2-T3) that began with blood markers, HR and BP assessments, followed by nude body weight assessment, and the POMS and VAS questionnaires. After 60 min, a fourth battery (V2-T4) was performed that included HR, BP, and blood markers. After sitting quietly for another 60 min a fifth battery assessment was performed (V2-T5) that included participants' USG, POMS and VAS questionnaires, HR, BP, blood markers, and total body hydration. Visits 3 (V3) and 4 (V4) followed the same protocol except a different randomized drink (16 oz. of CE, MIDS, or W) was consumed; all of which were separated by approximately one week. RESULTS: No differences occurred between conditions for 5-km time trial completion, indirect calorimetry outcomes during 5-km time trials, USG, or nude mass measurements (p > 0.05 for all relevant statistical tests). However, blood potassium and the sodium/potassium ratio displayed significant interactions (p < 0.05), and post hoc testing indicated these values were better maintained in the MIDS versus other conditions. Post-exercise cramp prevalence was greater in the CE (p < 0.05) and trended higher with W (p = 0.083) compared to the MIDS condition. Post-exercise cramp severity was also elevated with the W and CE beverages (p < 0.05) but not the MIDS (p = 0.211). CONCLUSIONS: The MIDS did not affect 5-km time trial performance but exhibited favorable effects on blood electrolyte and post-exercise self-reporting cramp outcomes compared to the CE and W drinks.


Assuntos
Equilíbrio Hidroeletrolítico , Água , Adulto , Feminino , Humanos , Masculino , Adulto Jovem , Aminoácidos , Bebidas , Carboidratos da Dieta/farmacologia , Eletrólitos , Cãibra Muscular , Potássio , Distribuição Aleatória
2.
Nutrients ; 10(9)2018 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-30200582

RESUMO

We investigated the effects of whey protein (WP) supplementation on body composition and physical performance in soldiers participating in Army Initial Entry Training (IET). Sixty-nine, male United States Army soldiers volunteered for supplementation with either twice daily whey protein (WP, 77 g/day protein, ~580 kcal/day; n = 34, age = 19 ± 1 year, height = 173 ± 6 cm, weight = 73.4 ± 12.7 kg) or energy-matched carbohydrate (CHO) drinks (CHO, 127 g/day carbohydrate, ~580 kcal/day; n = 35, age = 19 ± 1 year, height = 173 ± 5 cm, weight = 72.3 ± 10.9 kg) for eight weeks during IET. Physical performance was evaluated using the Army Physical Fitness Test during weeks two and eight. Body composition was assessed using 7-site skinfold assessment during weeks one and nine. Post-testing push-up performance averaged 7 repetitions higher in the WP compared to the CHO group (F = 10.1, p < 0.001) when controlling for baseline. There was a significant decrease in fat mass at post-training (F = 4.63, p = 0.04), but no significant change in run performance (F = 3.50, p = 0.065) or fat-free mass (F = 0.70, p = 0.41). Effect sizes for fat-free mass gains were large for both the WP (Cohen's d = 0.44) and CHO (Cohen's d = 0.42) groups. WP had a large effect on fat mass (FM) loss (Cohen's d = -0.67), while CHO had a medium effect (Cohen's d = -0.40). Twice daily supplementation with WP improved push-up performance and potentiated reductions in fat mass during IET training in comparison to CHO supplementation.


Assuntos
Composição Corporal , Carboidratos da Dieta/administração & dosagem , Suplementos Nutricionais , Militares , Valor Nutritivo , Condicionamento Físico Humano/métodos , Aptidão Física , Proteínas do Soro do Leite/administração & dosagem , Adiposidade , Adolescente , Método Duplo-Cego , Humanos , Masculino , Força Muscular , Estado Nutricional , Resistência Física , Fatores de Tempo , Adulto Jovem
3.
Sci Rep ; 8(1): 11151, 2018 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-30042516

RESUMO

It is currently unclear as to whether sex hormones are significantly affected by soy or whey protein consumption. Additionally, estrogenic signaling may be potentiated via soy protein supplementation due to the presence of phytoestrogenic isoflavones. Limited also evidence suggests that whey protein supplementation may increase androgenic signaling. Therefore, the purpose of this study was to examine the effects of soy protein concentrate (SPC), whey protein concentrate (WPC), or placebo (PLA) supplementation on serum sex hormones, androgen signaling markers in muscle tissue, and estrogen signaling markers in subcutaneous (SQ) adipose tissue of previously untrained, college-aged men (n = 47, 20 ± 1 yrs) that resistance trained for 12 weeks. Fasting serum total testosterone increased pre- to post-training, but more so in subjects consuming WPC (p < 0.05), whereas serum 17ß-estradiol remained unaltered. SQ estrogen receptor alpha (ERα) protein expression and hormone-sensitive lipase mRNA increased with training regardless of supplementation. Muscle androgen receptor (AR) mRNA increased while ornithine decarboxylase mRNA (a gene target indicative of androgen signaling) decreased with training regardless of supplementation (p < 0.05). No significant interactions of supplement and time were observed for adipose tissue ERα/ß protein levels, muscle tissue AR protein levels, or mRNAs in either tissue indicative of altered estrogenic or androgenic activity. Interestingly, WPC had the largest effect on increasing type II muscle fiber cross sectional area values (Cohen's d = 1.30), whereas SPC had the largest effect on increasing this metric in type I fibers (Cohen's d = 0.84). These data suggest that, while isoflavones were detected in SPC, chronic WPC or SPC supplementation did not appreciably affect biomarkers related to muscle androgenic signaling or SQ estrogenic signaling. The noted fiber type-specific responses to WPC and SPC supplementation warrant future research.


Assuntos
Suplementos Nutricionais , Genisteína/administração & dosagem , Isoflavonas/administração & dosagem , Fitoestrógenos/administração & dosagem , Extratos Vegetais/administração & dosagem , Treinamento Resistido , Proteínas de Soja/química , Proteínas do Soro do Leite/química , Tecido Adiposo/metabolismo , Adulto , Estradiol/sangue , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Humanos , Masculino , Fibras Musculares de Contração Rápida/metabolismo , Fibras Musculares de Contração Lenta/metabolismo , Músculo Esquelético/metabolismo , Ornitina Descarboxilase/metabolismo , Receptores Androgênicos/metabolismo , Esterol Esterase/metabolismo , Testosterona/sangue , Adulto Jovem
4.
Nutrients ; 9(9)2017 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-28869573

RESUMO

We sought to determine the effects of L-leucine (LEU) or different protein supplements standardized to LEU (~3.0 g/serving) on changes in body composition, strength, and histological attributes in skeletal muscle and adipose tissue. Seventy-five untrained, college-aged males (mean ± standard error of the mean (SE); age = 21 ± 1 years, body mass = 79.2 ± 0.3 kg) were randomly assigned to an isocaloric, lipid-, and organoleptically-matched maltodextrin placebo (PLA, n = 15), LEU (n = 14), whey protein concentrate (WPC, n = 17), whey protein hydrolysate (WPH, n = 14), or soy protein concentrate (SPC, n = 15) group. Participants performed whole-body resistance training three days per week for 12 weeks while consuming supplements twice daily. Skeletal muscle and subcutaneous (SQ) fat biopsies were obtained at baseline (T1) and ~72 h following the last day of training (T39). Tissue samples were analyzed for changes in type I and II fiber cross sectional area (CSA), non-fiber specific satellite cell count, and SQ adipocyte CSA. On average, all supplement groups including PLA exhibited similar training volumes and experienced statistically similar increases in total body skeletal muscle mass determined by dual X-ray absorptiometry (+2.2 kg; time p = 0.024) and type I and II fiber CSA increases (+394 µm² and +927 µm²; time p < 0.001 and 0.024, respectively). Notably, all groups reported increasing Calorie intakes ~600-800 kcal/day from T1 to T39 (time p < 0.001), and all groups consumed at least 1.1 g/kg/day of protein at T1 and 1.3 g/kg/day at T39. There was a training, but no supplementation, effect regarding the reduction in SQ adipocyte CSA (-210 µm²; time p = 0.001). Interestingly, satellite cell counts within the WPC (p < 0.05) and WPH (p < 0.05) groups were greater at T39 relative to T1. In summary, LEU or protein supplementation (standardized to LEU content) does not provide added benefit in increasing whole-body skeletal muscle mass or strength above PLA following 3 months of training in previously untrained college-aged males that increase Calorie intakes with resistance training and consume above the recommended daily intake of protein throughout training. However, whey protein supplementation increases skeletal muscle satellite cell number in this population, and this phenomena may promote more favorable training adaptations over more prolonged periods.


Assuntos
Adiposidade , Proteínas Alimentares/administração & dosagem , Suplementos Nutricionais , Leucina/administração & dosagem , Força Muscular , Hidrolisados de Proteína/administração & dosagem , Músculo Quadríceps/fisiologia , Treinamento Resistido , Proteínas de Soja/administração & dosagem , Gordura Subcutânea/fisiologia , Proteínas do Soro do Leite/administração & dosagem , Absorciometria de Fóton , Alabama , Biópsia , Proteínas Alimentares/efeitos adversos , Suplementos Nutricionais/efeitos adversos , Método Duplo-Cego , Ingestão de Energia , Humanos , Leucina/efeitos adversos , Masculino , Hidrolisados de Proteína/efeitos adversos , Músculo Quadríceps/citologia , Músculo Quadríceps/diagnóstico por imagem , Proteínas de Soja/efeitos adversos , Gordura Subcutânea/citologia , Gordura Subcutânea/diagnóstico por imagem , Fatores de Tempo , Resultado do Tratamento , Ultrassonografia , Proteínas do Soro do Leite/efeitos adversos , Adulto Jovem
5.
J Am Coll Nutr ; 36(1): 16-27, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27710436

RESUMO

OBJECTIVE: The objective of this study was to compare the chronic effects of different whey protein forms on body composition and performance when supplemented with resistance training. METHODS: Resistance-trained men (N = 56, 21.4 ± 0.4 years, 79.5 ± 1.0 kg) participated in an 8-week resistance training regimen (2 upper-body sessions and 2 lower-body sessions per week) and received one of 4 double-blinded treatments: 30 g/serving carbohydrate placebo (PLA) or 30 g/serving protein from either (a) 80% whey protein concentrate (WPC), (b) high-lactoferrin-containing WPC (WPC-L), or (c) extensively hydrolyzed WPC (WPH). All subjects consumed 2 servings of treatment per day; specifically, once immediately before and after training and between meals on nontraining days. Blood collection, one repetition maximum (1RM) testing for bench press and hack squat, and body composition assessment using dual-energy x-ray absorptiometry (DXA) occurred prior to training and 48 hours following the last training session. RESULTS: Total body skeletal muscle mass increased in all groups (p < 0.0125). There were similar between-group increases in upper-body (4%-7%, analysis of covariance [ANCOVA] interaction p = 0.73) and lower-body (24%-35%, ANCOVA interaction p = 0.85) 1RM strength following the intervention. Remarkably, WPH reduced fat mass (-6%), which was significantly different from PLA (+4.4%, p < 0.0125). No time or between-group differences were present for serum markers of health, metabolism, or muscle damage, with the exception of blood urea nitrogen being significantly lower for WPH than WPC (p < 0.05) following the intervention. CONCLUSIONS: WPH may augment fat loss but did not provide any other advantages when used in combination with resistance training. More mechanistic research is needed to examine how WPH affects adipose tissue physiology.


Assuntos
Exercício Físico/fisiologia , Treinamento Resistido , Proteínas do Soro do Leite/administração & dosagem , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/fisiologia , Adulto , Composição Corporal/efeitos dos fármacos , Suplementos Nutricionais , Método Duplo-Cego , Humanos , Lactoferrina/administração & dosagem , Masculino , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiologia , Hidrolisados de Proteína/administração & dosagem , Adulto Jovem
6.
Nutr Metab (Lond) ; 11: 19, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24822076

RESUMO

BACKGROUND: We examined if a purported anti-inflammatory supplement (AF) abrogated Western-diet (WD)-induced liver pathology in rats. AF contained: 1) protein concentrates from bovine colostrum and avian egg yolk; 2) herbal adaptogens and antioxidants; and 3) acetyl-L-carnitine. METHODS: Nine month-old male Brown Norway rats were allowed ad libitum access to WD for 41-43 days and randomly assigned to WD + AF feeding twice daily for the last 31-33 days (n = 8), or WD and water-placebo feeding twice daily for the last 31-33 days (n = 8). Rats fed a low-fat/low-sucrose diet (CTL, n = 6) for 41-43 days and administered a water-placebo twice daily for the last 31-33 days were also studied. Twenty-four hours following the last gavage-feed, liver samples were analyzed for: a) select mRNAs (via RT-PCR) as well as genome-wide mRNA expression patterns (via RNA-seq); b) lipid deposition; and, c) protein carbonyl and total antioxidant capacity (TAC). Serum was also examined for TAC, 8-isoprostane and clinical chemistry markers. RESULTS: WD + AF rats experienced a reduction in liver Tnf-α mRNA (-2.8-fold, p < 0.01). Serum and liver TAC was lower in WD + AF versus WD and CTL rats (p < 0.05), likely due to exogenous antioxidant ingredients provided through AF as evidenced by a tendency for mitochondrial SOD2 mRNA to increase in WD + AF versus CTL rats (p = 0.07). Liver fat deposition nor liver protein carbonyl content differed between WD + AF versus WD rats, although liver protein carbonyls tended to be lower in WD + AF versus CTL rats (p = 0.08). RNA-seq revealed that 19 liver mRNAs differed between WD + AF versus WD when both groups were compared with CTL rats (+/- 1.5-fold, p < 0.01). Bioinformatics suggest that AF prevented WD-induced alterations in select genes related to the transport and metabolism of carbohydrates in favor of select genes related to lipid transport and metabolism. Finally, serum clinical safety markers and liver pathology (via lesion counting) suggests that chronic consumption of AF was well tolerated. CONCLUSIONS: AF supplementation elicits select metabolic, anti-inflammatory, and anti-oxidant properties which was in spite of WD feeding and persisted up to 24 hours after receiving a final dose.

7.
Appl Physiol Nutr Metab ; 35(5): 607-16, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20962916

RESUMO

The aim of this study was to evaluate the combined effects of a 10-week exercise program with ingestion of caffeine and epigallocatechin-3-gallate (EGCG) on body composition, cardiovascular fitness, and strength in overweight and obese women. In a double-blind, placebo-controlled approach, overweight and obese women (n = 27) were randomly assigned to treatment groups with exercise (an active-supplementing group with exercise (EX-Act) and a placebo group with exercise (EX-PL)) or without exercise (an active-supplementing group without exercise (NEX-Act) and a placebo group without exercise (NEX-PL)). All participants consumed 1 drink per day for 10 weeks; EX-Act and EX-PL participated in a concurrent endurance and resistance training program. Changes in body composition were assessed using a 4-compartment model. Changes in muscle mass (MM) were evaluated using a DXA-derived appendicular lean-soft tissue equation. There was a significant time × treatment interaction for MM (p = 0.026) and total cholesterol (TC) (p = 0.047), and a significant time × training interaction for peak oxygen consumption (p = 0.046) and upper-body and lower-body strength (p < 0.05). Significant differences between the EX groups and NEX groups for percentage change in MM and peak oxygen consumption, and upper-body and lower-body strength, were revealed. Clinical markers for hepatic and renal function revealed no adverse effects. TC significantly decreased for the active-supplementing groups (EX-Act, NEX-Act). The current study suggests that implementing a caffeine-EGCG-containing drink prior to exercise may improve MM, fitness, and lipid profiles in overweight women.


Assuntos
Cafeína/administração & dosagem , Catequina/análogos & derivados , Exercício Físico/fisiologia , Obesidade/tratamento farmacológico , Resistência Física/efeitos dos fármacos , Adolescente , Adulto , Antioxidantes/administração & dosagem , Composição Corporal/efeitos dos fármacos , Fenômenos Fisiológicos Cardiovasculares/efeitos dos fármacos , Catequina/administração & dosagem , Terapia Combinada , Feminino , Humanos , Lipídeos/sangue , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Inibidores de Fosfodiesterase/administração & dosagem , Aptidão Física/fisiologia , Adulto Jovem
8.
Nutr Metab (Lond) ; 7: 51, 2010 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-20565767

RESUMO

Regardless of age or gender, resistance training or provision of adequate amounts of dietary protein (PRO) or essential amino acids (EAA) can increase muscle protein synthesis (MPS) in healthy adults. Combined PRO or EAA ingestion proximal to resistance training, however, can augment the post-exercise MPS response and has been shown to elicit a greater anabolic effect than exercise plus carbohydrate. Unfortunately, chronic/adaptive response data comparing the effects of different protein sources is limited. A growing body of evidence does, however, suggest that dairy PRO, and whey in particular may: 1) stimulate the greatest rise in MPS, 2) result in greater muscle cross-sectional area when combined with chronic resistance training, and 3) at least in younger individuals, enhance exercise recovery. Therefore, this review will focus on whey protein supplementation and its effects on skeletal muscle mass when combined with heavy resistance training.

9.
Eur J Appl Physiol ; 105(3): 357-63, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18989693

RESUMO

The purpose of this study was to determine the effects of beta-alanine supplementation and high-intensity interval training (HIIT) on electromyographic fatigue threshold (EMG(FT)) and efficiency of electrical activity (EEA). A total of 46 men completed four, 2-min work bouts on a cycle ergometer. Using bipolar surface electrodes, the EMG amplitude was averaged and plotted over the 2-min. The resulting slopes were used to calculate EMG(FT) and EEA. Following initial testing, all participants were randomly assigned to either placebo (PL; n = 18), beta-alanine (BA; n = 18) or control groups (CON; n = 10). Following randomization, participants engaged in 6 weeks of HIIT training. Significant improvements in EMG(FT) and EEA resulted for both training groups. In conclusion, HIIT appeared to be the primary stimulus effecting EMG(FT) or EEA, suggesting adaptations from HIIT may be more influential than increasing skeletal muscle carnosine levels on delaying fatigue in recreationally active men.


Assuntos
Adaptação Biológica/fisiologia , Fadiga Muscular/fisiologia , Resistência Física/fisiologia , beta-Alanina/farmacologia , Adaptação Biológica/efeitos dos fármacos , Adulto , Ciclismo/fisiologia , Carnosina/metabolismo , Eletromiografia , Teste de Esforço , Humanos , Masculino , Fadiga Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Resistência Física/efeitos dos fármacos , Esforço Físico/efeitos dos fármacos , Esforço Físico/fisiologia , Aptidão Física/fisiologia , beta-Alanina/metabolismo
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